<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div style="border: 1px solid red">dolaksxkasp</div>
    <div style="border:1px solid black;
                width: 500px;
                font-size: 16px;
                text-align: center;
                line-height: 48px;
                font-weight: bold;
    ">sxs;xl;ask;sa</div>

<!--solid是实线,border还有border-left，text-align为标签文本居中 ，line-height 大体意思为行高，bold为字体加粗 -->
</body>
</html>